/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.biff.formula;

import java.util.Stack;

/**
 * A cell reference in a formula
 */
abstract class UnaryOperator extends Operator implements ParsedThing {
    /**
     * Constructor
     */
    public UnaryOperator() {
    }

    /**
     * Reads the ptg data from the array starting at the specified position
     *
     * @param data the RPN array
     * @param pos the current position in the array, excluding the ptg identifier
     * @return the number of bytes read
     */
    public int read(byte[] data, int pos) {
        return 0;
    }

    /**
     * Gets the operands for this operator from the stack
     */
    public void getOperands(Stack s) {
        ParseItem o1 = (ParseItem) s.pop();

        add(o1);
    }

    /**
     * Gets the string
     *
     * @param buf
     */
    public void getString(StringBuffer buf) {
        ParseItem[] operands = getOperands();
        buf.append(getSymbol());
        operands[0].getString(buf);
    }

    /**
     * Adjusts all the relative cell references in this formula by the
     * amount specified.  Used when copying formulas
     *
     * @param colAdjust the amount to add on to each relative cell reference
     * @param rowAdjust the amount to add on to each relative row reference
     */
    public void adjustRelativeCellReferences(int colAdjust, int rowAdjust) {
        ParseItem[] operands = getOperands();
        operands[0].adjustRelativeCellReferences(colAdjust, rowAdjust);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was inserted
     * @param col the column number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    void columnInserted(int sheetIndex, int col, boolean currentSheet) {
        ParseItem[] operands = getOperands();
        operands[0].columnInserted(sheetIndex, col, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was removed
     * @param col the column number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    void columnRemoved(int sheetIndex, int col, boolean currentSheet) {
        ParseItem[] operands = getOperands();
        operands[0].columnRemoved(sheetIndex, col, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the row was inserted
     * @param row the row number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    void rowInserted(int sheetIndex, int row, boolean currentSheet) {
        ParseItem[] operands = getOperands();
        operands[0].rowInserted(sheetIndex, row, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the row was removed
     * @param row the row number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    void rowRemoved(int sheetIndex, int row, boolean currentSheet) {
        ParseItem[] operands = getOperands();
        operands[0].rowRemoved(sheetIndex, row, currentSheet);
    }

    /**
     * Gets the token representation of this item in RPN
     *
     * @return the bytes applicable to this formula
     */
    byte[] getBytes() {
        // Get the data for the operands
        ParseItem[] operands = getOperands();
        byte[] data = operands[0].getBytes();

        // Add on the operator byte
        byte[] newdata = new byte[data.length + 1];
        System.arraycopy(data, 0, newdata, 0, data.length);
        newdata[data.length] = getToken().getCode();

        return newdata;
    }

    /**
     * Abstract method which gets the binary operator string symbol
     *
     * @return the string symbol for this token
     */
    abstract String getSymbol();

    /**
     * Abstract method which gets the token for this operator
     *
     * @return the string symbol for this token
     */
    abstract Token getToken();

    /**
     * If this formula was on an imported sheet, check that
     * cell references to another sheet are warned appropriately
     * Does nothing, as operators don't have cell references
     */
    void handleImportedCellReferences() {
        ParseItem[] operands = getOperands();
        operands[0].handleImportedCellReferences();
    }


}
